Hi Eugenio,
If you are powered up on the 8.0-8.6 m2 it should work nicely on the Futura 122.
If you are not powered up (and you need to go out and experiment to figure out what the windspeed and water surface conditions are that will support easily planing on the
Futura 122) then your Free Formula 157 will be the better choice.
I think the Futura 122 is really optimized at about 7.5 m2.
You can sail a meter larger, but your wider FF-157 will still plane earlier with the 9.5 m2.
If you get windspeeds of 12 knots (F4 Bft/6.2 m/s) or more, then the Futura 122 with the 8.0 m2 + rig would seem the best way to go at your weight.
Hope this helps,